EARTH STRUCTURE AND PLATE TECTONICS

1
CHAPTER 5

• EARTH STRUCTURE AND PLATE TECTONICS

2
SEISMIC WAVES

• BODY WAVES
• PRIMARY WAVES P - WAVES
• SECONDARY WAVES S - WAVES
• SURFACE WAVES

3
SEISMOGRAPH
4
SURFACE WAVES
S - WAVES
P - WAVES
SEISMIC WAVES
5
MOVEMENT OF P - WAVES
6
MOVEMENT OF S - WAVES
7
THE DIVISIONS OF INNER SPACE

• SEISMIC DISCONTINUITIES
• MOHOROVICIC ( CRUST/ MANTLE BOUNDARY)
• GUTENBERG ( MANTLE/CORE BOUNDARY)
• THE CORE
• OUTER CORE (LIQUID)
• INNER CORE (SOLID)
• THE MANTLE (SOLID)

8
UPPER MANTLE
LOWER MANTLE
OUTER CORE
INNER CORE
9
MOVEMENT OF BODY WAVES
10
COMPOSITION OF THE CORE

• IRON
• NICKEL
• MINOR ELEMENTS
• CORE DENSITY IS 5.5gms/cm3

11
COMPOSITION OF THE MANTLE

• PERIDOTITE ULTRA BASIC IGNEOUS ROCK
• DENSITY 4.5 GMS/CM3
• UPPER MANTLE
• ASTHENOSPHERE
• LITHOSPHERE

12
COMPOSITION OF THE CRUST

• OCEANIC CRUST (YOUNG)
• COMPOSITION BASALT
• DENSITY 3.0 GMS/CM3
• CONTINENTAL CRUST (OLD)
• COMPOSITION GRANITE
• DENSITY 2.7GMS/CM3

13
OCEANIC CRUST
CONTINENTAL CRUST
14
MEASURING STRUCTURE

• STRIKE
• A MEASUREMENT OF THE TREND DIRECTION OF THE
  BEDDING PLANES.
• DIP
• A MEASUREMENT OF HOW MUCH THE BEDDING PLANES ARE
  INCLINED FROM HORIZONTAL.

15
STRIKE AND DIP
DIP ANGLE
16
CRUSTAL STRUCTURE

• FAULTS
• NORMAL
• OBLIQUE NORMAL FAULT
• REVERSE
• THRUST
• STRIKE SLIP (LATERAL)
• FOLDS
• ANTICLINES
• DOMES
• SYNCLINES
• BASINS

17
TETON MOUNTAINS, WYOMING
FAULT BLOCK MOUNTAINS
18
TYPES OF FAULTS
19
NORMAL FAULT
20
NORMAL FAULT
21
REVERSE FAULT
22
FOLDED STRATA
23
ANTICLINE
SYNCLINE
MONOCLINE
BASIN
DOME
FOLDS
24
ANTICLINE
25
SYNCLINE
26
PLATE TECTONICS

• THE THEORY THAT EXPLAINS THE TECTONIC BEHAVIOR OF
  THE CRUST OF THE EARTH IN TERMS OF SEVERAL
  MOVING PLATES THAT ARE FORMED BY VOLCANIC
  ACTIVITY AT OCEANIC RIDGES AND DESTROYED ALONG
  GREAT OCEAN TRENCHES.

27
FRAGMENTED CONTINENTS CONTINENTAL DRIFT

• EDUARD SUESS
• GONDWANALAND
• ALFRED WEGENER
• PANGEA
• LAURASIA
• PANTHALASSA

28
(No Transcript)
29
EVIDENCE FOR CONTINENTAL DRIFT

• FIT OF THE CONTINENTS
• DISTRIBUTION OF GLACIAL ICE
• LITHOLOGIC CORRELATIONS
• FAUNAL CORRELATIONS

30
FIT OF THE CONTINENTS
31
DISTRIBUTION OF GLACIAL ICE
32
LITHOLOGIC CORRELATION
33
MESOSAURUS
GLOSSOPTERIS
FAUNAL CORRELATION
34
PALEOMAGNETISM

• REMANENT MAGNETISM
• IGNEOUS ROCKS
• CURRIE TEMPERATURE
• DEPOSITIONAL REMANENT MAGNETISM
• APPARENT POLAR WANDERING

35

EARTH'S PRESENT MAGNETISM
36
(No Transcript)
37
APPARENT POLAR WANDERING
38
PLATE TECTONIC CONCEPTS

• THE LITHOSPHERE IS CONSTRUCTED OF 7 MAJOR AND
  ABOUT 20 MINOR PLATES
• MOVEMENT OF THE PLATES CAUSES THEM TO CONVERGE,
  DIVERGE OR SLIDE PAST ONE ANOTHER.
• PLATE MOVEMENT IS A RESULT OF CONVECTION CELLS IN
  THE MANTLE , RIDGE - PUSH AND SLAB - PULL

39
(No Transcript)
40
(No Transcript)
41
EARTH'S PLATES
42
TYPES OF PLATE BOUNDARIES

• CONVERGENT
• OCEAN/CONTINENT
• OCEAN/OCEAN
• CONTINENT/CONTINENT
• DIVERGENT SEA FLOOR SPREADING
• OCEAN/OCEAN
• CONTINENT/CONTINENT
• TRANSFORM

43
CONVERGENT
44
CONVERGENT
45
CONVERGENT
46
DIVERGENT
OCEAN / OCEAN
47
DIVERGENT
CONTINENT / CONTINENT
48
TRANSFORM FAULT
49
CRUSTAL BEHAVIOR AT PLATE BOUNDARIES

• VOLCANIC ACTIVITY
• RING OF FIRE
• MOUNTAIN BUILDING
• SEA FLOOR SPREADING

50
VOLCANIC ACTIVITY
51
MT. BUILDING
52
MT. BUILDING
53
MT. BUILDING
54
MT. BUILDING
55
SEA FLOOR SPREADING
56
THERMAL PLUMES
57
(No Transcript)
58
(No Transcript)
59
TESTS OF PLATE TECTONICS

• PALEOMAGNETISM
• OCEANIC SEDIMENT
• MEASUREMENT FROM SPACE
• SEISMOLOGICAL EVIDENCE

60
PALEOMAGNETISM
61
PALEOMAGNETISM
62
PALEOMAGNETISM
63
PALEOMAGNETISM
64
PALEOMAGNETISM
65
OCEANIC SEDIMENT
66
MEASUREMENT FROM SPACE
67
MEASUREMENT FROM SPACE
68
SEISMIC EVIDENCE
69
HOT SPOTS
70
HOT SPOT
71
(No Transcript)
72
HAWAII VOLCANOES NP
HOT SPOT
73
ALIEN TERRANES

• ALLOCHTHONOUS OR EXOTIC TERRANES

74
EXOTIC TERRANES